Marin Municipal Water District (MMWD) will install more than half a mile (3,020 feet) of new water distribution pipeline on Bon Air Road in Larkspur and Gate 5 Road in Sausalito as part of the district's capital and fire flow improvement programs to eliminate aging cast iron pipes with a high concentration of leaks and vulnerable to breaks during earthquakes.
Part of the Larkspur project is being timed to coincide with the City of Larkspur’s plan to replace the bridge across Corte Madera Creek, which requires replacement of the piping on the bridge anyway. The pipes near Marin General Hospital and in the intersection of Bon Air Road and South Eliseo Drive have been prioritized for replacement as part of the district’s fire flow improvement plan. Five-hundred feet of 6-inch cast iron pipe installed in 1950 near the hospital and approximately 500 feet of 8-inch welded steel pipe installed in 1986 will be replaced with 1,000 feet of new 12-inch welded steel pipe.
In Sausalito on Gate 5 Road, approximately 2,000 feet of 8-inch cast iron piping installed in 1956 will be replaced with new 12-inch and 8-inch welded steel piping. Cast iron pipes in this low-lying area are prone to leaks and breaks because of the corrosive, high salt moisture in the soil.
Work is estimated to start in mid-May beginning with the project in Larkspur. The Larkspur section will be completed before the Sausalito section is started and the entire project should be completed by mid-August. Both the contractor and MMWD will make every effort to minimize traffic disruptions during construction.